Methods, Mobile Station and Base Station, for Extended Sharing of Uplink Packet Data Channels in a GSM Network

1. A method in a mobile station for enabling more than eight mobile stations to share one uplink Packet Data Channel in a Global System for Mobile Communications (GSM) network, wherein the method comprises: receiving two or more legacy Uplink State Flag (USF) values in respective downlink radio blocks in a set of two or more downlink radio blocks, each legacy USF value being one in a defined set of legacy USF values that are individually usable by legacy mobile stations that are not configured to jointly interpret the legacy USF values; jointly interpreting the two or more legacy USF values as a received combined USF value, formed as a combination of the two or more legacy USF values; determining whether the received combined USF value matches an assigned combined USF value that has been assigned to the mobile station, said assigned combined USF value comprising a unique combination of two or more of the legacy USF values from the defined set of legacy USF values; and transmitting packet data only when the received combined USF value matches the assigned combined USF value; wherein the assigned combined USF value is one among two or more assigned combined USF values that have been assigned to the mobile station, each assigned combined USF value having a different corresponding subset of uplink radio blocks, and wherein transmitting the packet data comprises transmitting the packet data on the subset of uplink radio blocks corresponding to the assigned combined USF value matching the received combined USF value.

2. The method of claim 1 , wherein receiving the two or more legacy USF values in the respective downlink radio blocks in the set of two or more downlink radio blocks comprises receiving the two or more legacy USF values in a predefined set of two or more downlink radio blocks.

3. The method of claim 1 , further comprising receiving the set of two or more downlink radio blocks on one or a combination of: two or more Packet Data Channels on different timeslots in a Time Division Multiple Access frame during one 20 millisecond radio block period, and two or more consecutive radio blocks on one Packet Data Channel; and wherein transmitting the packet data comprises transmitting the packet data on all or only a subset of uplink radio blocks corresponding to the set of two or more downlink radio blocks.

4. A method in a Global System for Mobile Communications (GSM) network for enabling more than eight mobile stations to share one uplink Packet Data Channel in the GSM network, wherein the method comprises: determining that a mobile station supports joint interpretation of legacy Uplink State Flag (USF) values, each legacy USF value being one in a defined set of legacy USF values that are individually usable by legacy mobile stations that are not configured to jointly interpret the legacy USF values; assigning more than one unique combination of legacy USF values to the mobile station as respective assigned combined USF values, where each assigned combined USF value corresponds to a different subset of uplink radio blocks, and controlling the subsets of uplink radio blocks transmitted on by the mobile station by transmitting selected ones of the assigned combined USF values to the mobile station, wherein each assigned combined USF value comprises a unique combination of two or more of the legacy USF values; and indicating an uplink transmission opportunity to the mobile station by transmitting the two or more legacy USF values comprising one of the assigned combined USF value in respective downlink radio blocks in a set of two or more downlink radio blocks.

5. The method of claim 4 , wherein the set of two or more downlink radio blocks comprises a predefined set of two or more downlink radio blocks.

6. The method of claim 4 , further comprising transmitting the set of two or more downlink radio blocks on either one or a combination of: two or more Packet Data Channels on different timeslots in a Time Division Multiple Access frame during one 20 millisecond radio block period, and two or more consecutive radio blocks on one Packet Data Channel; and wherein the method further includes receiving packet data from the mobile station on all or only a subset of uplink radio blocks corresponding to the set of two or more downlink radio blocks.

7. The method of claim 4 , further comprising assigning one of the legacy USF values comprising a given one of the assigned combined USF values to a legacy mobile station, such that said legacy USF value is used individually to indicate transmission opportunities to the legacy mobile station and is used jointly in the given one of the assigned combined USF values to indicate transmission opportunities to the mobile station.

8. A mobile station for enabling more than eight mobile stations to share one uplink Packet Data Channel in a Global System for Mobile Communications (GSM) network, wherein the mobile station comprises: a receiver configured to receive two or more legacy Uplink State Flag (USF) values in respective downlink radio blocks in a set of two or more downlink radio blocks, each legacy USF value being one in a defined set of legacy USF values that are individually usable by legacy mobile stations that are not configured to jointly interpret the legacy USF values; and a processor circuit operatively associated with the receiver and configured to: jointly interpret the two or more legacy USF values as a received combined USF value, formed as a combination of the two or more legacy USF values; determine whether the received combined USF value matches an assigned combined USF value that has been assigned to the mobile station, said assigned combined USF value comprising a unique combination of two or more of the legacy USF values from the defined set of legacy USF values; and transmit packet data via a transmitter of the mobile station, when the received combined USF value matches the assigned combined USF value; wherein the assigned combined USF value is one among two or more assigned combined USF values that have been assigned to the mobile station, each assigned combined USF value having a different corresponding subset of uplink radio blocks, and wherein the mobile station is configured to transmit the packet data on the subset of uplink radio blocks corresponding to the assigned combined USF value matching the received combined USF value.

9. The mobile station of claim 8 , wherein the mobile station is configured to receive the two or more legacy USF values in a predefined set of two or more downlink radio blocks.

10. The mobile station of claim 8 , wherein the mobile station is configured to receive the set of two or more downlink radio blocks on one or a combination of: two or more Packet Data Channels on different timeslots in a Time Division Multiple Access frame during one 20 millisecond radio block period, and two or more consecutive radio blocks on one Packet Data Channel; and wherein the mobile station is further configured to transmit the packet data on all or only a subset of uplink radio blocks corresponding to the set of two or more downlink radio blocks.

11. A base station for enabling more than eight mobile stations to share one uplink Packet Data Shared Channel in a Global System for Mobile Communications (GSM) network, wherein the base station comprises: a transmitter for transmitting to mobile stations; and a processor operatively associated with the transmitter and configured to: determine that a mobile station supports joint interpretation of legacy Uplink State Flag (USF) values, each legacy USF value being one in a defined set of legacy USF values that are individually usable by legacy mobile stations that are not configured to jointly interpret the legacy USF values; assign more than one unique combination of legacy USF values to the mobile station as respective assigned combined USF values, where each assigned combined USF value corresponds to a different subset of uplink radio blocks, and wherein the processor is further configured to control the subsets of uplink radio blocks transmitted on by the mobile station by transmitting selected ones of the assigned combined USF values to the mobile station, and whereing each assigned combined USF value comprises a unique combination of two or more of the legacy USF values; and indicate an uplink transmission opportunity to the mobile station by transmitting the two or more legacy USF values comprising the assigned combined USF value in respective downlink radio blocks in a set of two or more downlink radio blocks.

12. The base station of claim 11 , wherein the set of two or more downlink radio blocks comprises a predefined set of two or more downlink radio blocks.

13. The base station of claim 11 , wherein the base station is configured to transmit the set of two or more downlink radio blocks on either one or a combination of: two or more Packet Data Channels on different timeslots in a Time Division Multiple Access frame during one 20 millisecond radio block period, and two or more consecutive radio blocks on one Packet Data Channel; and wherein the base station is further configured to receive, via a receiver of the base station, packet data from the mobile station on all or only a subset of uplink radio blocks corresponding to the set of two or more downlink radio blocks.

14. The base station of claim 11 , wherein the processor is configured to assign one of the legacy USF values comprising a given one of the assigned combined USF value to a legacy mobile station, such that said legacy USF value is used individually to indicate transmission opportunities to the legacy mobile station and is used jointly in the given assigned combined USF value to indicate transmission opportunities to the mobile station.

15. A method at a base station for multiplexing mobile stations onto an Uplink Packet Data Channel (PDCH) in a Global System for Mobile Communication (GSM) network, said method comprising: receiving capability information for a first mobile station, indicating that the first mobile station is configured to jointly interpret legacy Uplink State Flag (USF) values, whereby the first mobile station forms combined USF values by combining two or more legacy USF values received by the first mobile station, each legacy USF value taken from a defined set of legacy USF values that are individually usable in the GSM network to identify individual mobile stations multiplexed onto the same uplink PDCH; assigning a downlink radio block set of two or more downlink radio blocks to the first mobile station, and assigning a combined USF value to the first mobile station as a unique combination of two or more of the legacy USF values from the defined set of legacy USF values; transmitting information to the first mobile station, indicating the assigned downlink radio block set and the assigned combined USF value; identifying an uplink transmission opportunity for the first mobile station on the uplink PDCH by transmitting respective ones of the two or more legacy USF values comprising the assigned combined USF value in respective ones of the downlink radio blocks comprising the assigned downlink radio block set; and determining that a second mobile station does not support joint interpretation of the legacy USF values, and multiplexing the second mobile station onto the uplink PDCH by assigning a selected one of the legacy USF values from the defined set of legacy USF values to the second mobile station, and identifying transmission opportunities for the second mobile station on the uplink PDCH by transmitting the selected legacy USF value on a selected downlink radio block; wherein the selected legacy USF value is one of the legacy USF values comprising the assigned combined USF value of the first mobile station, such that the selected USF value is used for multiplexing the first mobile station onto the uplink PDCH and reused for multiplexing the second mobile station onto the uplink PDCH.

16. A method at a first mobile station configured for operation in a Global System for Mobile Communication (GSM) network, said method comprising: transmitting capability information to a base station, indicating that the first mobile station is configured to jointly interpret legacy Uplink State Flag (USF) values, whereby the first mobile station forms combined USF values by combining two or more legacy USF values received by the first mobile station, each such legacy USF value taken from a defined set of legacy USF values that are individually usable in the GSM network to identify individual mobile stations multiplexed onto a same uplink Packet Data Channel (PDCH); receiving information from the base station indicating an assigned downlink radio block set of two or more downlink radio blocks, and an assigned combined USF value indicating a unique combination of two or more of the legacy USF values from the defined set of legacy USF values, wherein the received assigned combined USF value is one among two or more assigned combined USF values that have been assigned to the mobile station, each assigned combined USF value having a different corresponding subset of uplink radio blocks; and responsive to detecting that the unique combination of legacy USF values is received in the assigned downlink radio block set, transmitting uplink packet data in one or more uplink radio blocks corresponding to the assigned downlink radio block set, wherein transmitting the packet data comprises transmitting the packet data on the subset of uplink radio blocks corresponding to the assigned combined USF value matching the received combined USF value.